Absorbent article having stain resistant properties

ABSTRACT

A sanitary napkin including a body facing surface, a portion adapted to be arranged over the vaginal opening during use, a first colored portion, said colored portion extending over at least the portion of the napkin to be placed over the vaginal opening during use, a noncolored portion, wherein said first colored portion has a first color as measured from said body facing surface prior to staining, wherein the first colored portion has a second color as measured from said body facing surface after staining, wherein the first color has an average L value greater than 80; and wherein a Δa* between said first color and said second color is less than 18.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Application No. 60/772,684 filed onFeb. 13, 2006, the entire contents of which are incorporated byreference herein.

FIELD OF THE INVENTION

The present invention generally relates to absorbent articles such as afeminine sanitary napkins. More particularly, the present inventionrelates to a sanitary napkin having improved stain resistant properties.

BACKGROUND OF THE INVENTION

Sanitary napkins intended to absorb menstrual fluid are well known inthe art. Most sanitary napkins in use today include a liquid permeablecover layer, a liquid impermeable barrier layer, and an absorbent systemarranged between the cover layer and the barrier layer. The absorbentsystem may comprise a single layer absorbent material or may comprisemultiple layers.

A disadvantage of prior art articles of the type described above is thatonce menstrual fluid is absorbed into the article the red color of themenstrual fluid is visible from the top surface of the article. Theobservation of the red color of the menstrual fluid from the top surfaceof the article has been identified as being unsightly and undesirable byusers.

In view of the above problem, attempts have been made in the prior artto “mask” the stain produced by menstrual fluid, that is to minimize thevisibility of the menstrual fluid from the top surface of the articleafter the fluid has been absorbed into the article. Various articleconfigurations have been disclosed in the prior art adapted to maskmenstrual fluid, i.e. intended to prevent the menstrual fluid from beingviewed Although some prior art articles are effective at maskingmenstrual fluid, it has been discovered that such articles have certainshortcomings. For example, many of the prior art articles adapted tomask menstrual fluid disclosed in the prior art employ a dark coloredlayer that functions to hide the menstrual fluid from view. However,such dark layers are also visible form the top surface of the napkin andare perceived as undesirable since the dark color suggests that thenapkin is not hygienic or clean.

It has been also been discovered that although users do not like the redappearance of menstrual fluid when visible form the top surface of asanitary napkin they do not desire that the menstrual fluid becompletely blocked or masked from view. In particular, it has beendiscovered that users desire that the menstrual fluid be visible fromthe top surface of the napkin since the presence of the menstrual fluidreassures the user that they are menstruating in a healthy manner.

In view of the foregoing, it is an object of the present invention toprovide a sanitary napkin that permits menstrual fluid be visible fromthe top surface of the napkin while at the same time minimizing the redappearance of the menstrual fluid from the top surface of the napkin. Inaddition, it is another object of the present invention to provide asanitary napkin having these properties that does not have a darkcolored appearance from the body facing surface of the napkin prior touse.

SUMMARY OF THE INVENTION

In view of the foregoing objectives, the present invention provides asanitary napkin including a body facing surface, a portion adapted to bearranged over the vaginal opening during use, a first colored portion,said colored portion extending over at least the portion of the napkinto be placed over the vaginal opening during use, a noncolored portion,wherein said first colored portion has a first color as measured fromsaid body facing surface prior to staining, wherein the first coloredportion has a second color as measured from said body facing surfaceafter staining, wherein the first color has an average L value greaterthan 80; and wherein a Δa* between said first color and said secondcolor is less than 18.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 a is a schematic view of a three-dimensional film for use inabsorbent articles according the present invention;

FIG. 1 b is a partially broken-away perspective view of the film shownin FIG. 1 a taken along line 1B in FIG. 1 a;

FIG. 1 c is an enlarged photomicrograph of the three-dimensional filmschematically shown in FIG. 1 a, showing a top surface thereof;

FIG. 1 d is an enlarged photomicrograph of the three-dimensional filmshown in FIG. 1 c, showing a bottom surface thereof;

FIG. 1 e is a schematic view of a three-dimensional film, according asecond embodiment, for use in absorbent articles according to thepresent invention;

FIG. 1 f is a partially broken away perspective view of the film shownin FIG. 1 e taken along line “1f” in FIG. 1 e;

FIG. 1 g is a photomicrograph of the top surface of thethree-dimensional film schematically shown in FIG. 1 e;

FIG. 1 h is a photomicrograph of the bottom surface of thethree-dimensional film shown in FIG. 1 g;

FIG. 1 i is an enlarged photomicrograph of a portion of thethree-dimensional film shown in FIG. 1 g, said portion corresponding tothe portion of the film encircled by the circle “1f” in FIG. 1 e;

FIG. 1 j is an photomicrograph of the portion of the three-dimensionalfilm shown in FIG. 1 i showing a bottom surface thereof;,

FIG. 2 is a schematic illustration of one type of three dimensionaltopographical support member useful to make films useful in absorbentarticles according to the present invention;

FIG. 3 is a schematic illustration of an apparatus for laser sculpting aworkpiece to form a three dimensional topographical support memberuseful to make a film used in absorbent articles according to thepresent invention;

FIG. 4 is a schematic illustration of a computer control system for theapparatus of FIG. 3;

FIG. 5 is a graphical representation of a file to laser sculpt aworkpiece to produce a three dimensional topographical support memberfor producing an apertured film shown in FIGS. 1 a-1 d;

FIG. 5 a is a graphical representation of the file shown in FIG. 5showing an enlarged portion thereof;

FIG. 5 b is a graphical representation of a file to laser sculpt aworkpiece to produce a three dimensional topographical support memberfor producing the apertured film shown in FIGS. 1 e-1 j;

FIG. 5 c is an enlarged portion of the graphical representation of thefile shown in FIG. 5 b showing the portion of the file encircled by thecircle 5 c in FIG. 5 b;

FIG. 5 d is an enlarged portion of the graphical representation of thefile shown in 5 b showing the portion of the file encircled by thecircle 5 d in FIG. 5 b;

FIG. 5 e is an enlarged portion of the graphical representation shown inFIG. 5 d showing the portion of the file encircled by the circle 5 e inFIG. 5 d;

FIG. 6 is a photomicrograph of a workpiece after it was sculptedutilizing the file of FIG. 5;

FIG. 6 a is a photomicrograph of a workpiece after it was sculpted usingthe file shown in FIGS. 5 b-5 e;

FIG. 6 b is a enlarged portion of the workpiece shown in FIG. 6 a, saidenlarged portion corresponding to the area encircled by the circle 6 bin FIG. 6 a;

FIG. 7 is a view of a support member used to make a film according tothe invention in place on a film-forming apparatus;

FIG. 8 is a schematic view of an apparatus for producing an aperturedfilm according to the present invention;

FIG. 9 is a schematic view of the circled portion of FIG. 8;

FIG. 10 is a graphical representation of a file to drill a workpieceusing raster scan drilling to produce a three dimensional topographicalsupport member for producing an apertured film;

FIG. 11 is a top plan view of an absorbent article according to thepresent invention;

FIG. 12 is an exploded perspective view of the absorbent article shownin FIG. 10; and

FIG. 13 is a perspective view of a portion of the absorbent articleshown in FIG. 10 with the layers thereof partially cut away to revealthe underlying structure.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to an absorbent article, such as afeminine sanitary napkin, having improved stain resistant properties.More particularly the sanitary napkin according to the present inventionminimizes the “red” appearance of the menstrual fluid after fluid isabsorbed by the napkin while the napkin prior to staining has a lightoverall appearance.

Color measurements provided herein use the CIE La*b* color system. TheLa*b* color system, also known as the Hunter color scale, is well knowto those skilled in the art. The La*b* system correlates to thesensitivity of the eye towards brightness or luminance and to colorchanges. The L value reflects the eye's sensitivity to brightness as oneobserves colors ranging from dark color to bright color and from gray towhite. L is defined as 0 for a surface that is non-reflecting black and100 for a surface that is non-fluorescing white. The variable a*represents the ratio of reflectance in the green region to reflectancein the red region and the variable b* represents the ratio ofreflectance in the blue region to the yellow region of theelectromagnetic spectrum.

The term “color” typically includes every value of the color space whichincludes black and white. However, for purposes of this application,when the term “color” or “colored” is used herein in describing the“colored portions” of the article it is intended to exclude black andwhite. As used herein, black is defined as L<25, −2<a*<2 and −2<b*<2. Asused herein, white is defined as L>90, −2<a*<2 and −2<b<2. The terms“noncolored” and white are used interchangeably herein.

The L, a*, and b* values for the “colored” areas of the sanitary napkin800, described in detail below, are the values as measured by a MinoltaCR-321 color measurement system, using the 3 mm aperture, from thebody-facing surface 801 of the napkin, unless otherwise specified.

Referring to FIG. 11, there is shown a first embodiment of the presentinvention, a sanitary napkin 800, showing the body-facing surface 801thereof. The sanitary napkin 800 generally includes at least a firstcolored portion 802 and at least a noncolored portion 803. The coloredportion 802 is arranged on the napkin so at least a portion of thecolored portion 802 is located in the area of the napkin intended to beplaced over the vaginal opening of the napkin during use. The napkin 800includes an imaginary transverse center line “a” and an imaginarylongitudinal center line “b”. In the embodiment of the napkin 800 shownin FIG. 11, the colored portion 802 extends along the longitudinallyextending center line “b”. In addition, the colored portion 802 issymmetrical with respect to the longitudinal center line “b” and thetransverse center line “a”.

The napkin 800 may optionally include a second colored portion 804. Inthe embodiment of the invention shown in FIG. 11, the second coloredportion 804 consists of a substantially oval shaped colored ring 805that is arranged to surround the first colored 802. The ring 805 isarranged in spaced relationship to the first colored portion 802 suchthat the ring 805 is separated from the first colored portion 802 by anoncolored area 806. The ring 805 preferably has a width “c” (See FIG.12) of between 1 mm and 5 mm. Preferably, as shown in FIGS. 11-13, thering 805 is “continuous”, i.e. the ring 805 is not interrupted by anynoncolored portions but rather is a continuous colored band thatentirely surrounds the first colored portion 802.

The first colored portion 802 preferably extends over about 15% to about40% of the surface of the absorbent portion of the napkin 800 as viewedfrom the body facing surface 801 of the napkin. For purposes of the thisinvention “absorbent portion of the napkin” does not include the area ofnapkin defined by the wing areas 807. In the embodiment of the inventionshown in FIG. 11, the terminal edge of the absorbent portion of thenapkin is defined by the peripheral edge 847 of the transfer layer 846.The colored ring 805 preferably extends over about 3% to about 12% ofthe surface of the absorbent portion of the napkin 800 as viewed fromthe body facing surface of the napkin. Thus, the total colored portionsof the napkin 800, e.g. including the first colored portion 802 and thesecond colored portion 804, extend over about 18% to about 52% of theabsorbent portion of the napkin 800 as viewed from the body facingsurface of the napkin.

The embodiment of the sanitary napkin 800 shown in FIGS. 12-13 includesa cover layer 842, a first absorbent layer 846, a second absorbent layer848, a colored layer 849, and a barrier layer 850.

The colored layer 849 in one embodiment of the invention is an “internallayer” of the article, i.e. a layer located between the cover layer 842and barrier layer 850. The colored layer 849 may be a separate layerfrom the absorbent layers 846 and 848 as shown in FIG. 12. For example,the colored layer 849 may comprise a tissue layer or the like arrangedbetween the cover 842 and the transfer layer 846, the tissue layerhaving the colored portions preprinted thereon. Alternatively, thecolored layer may comprise either the first absorbent layer 846 and/orthe second absorbent layer 848. The colored layer may alternativelycomprise the cover layer or the internal surface, i.e. non-garmentfacing surface of the barrier. The colored areas, e.g. 802 and 804, arepreferably generated by applying a pigment or dye to the selected layer.The types of dyes and pigments suitable for use in the presentinvention, and their method of application, are well known to those ofskill in the art.

Although the colored portions 802 and 804 described above may be anumber of colors within the color spectrum it has been found thatcertain blue colors are particularly useful in the present invention. Inparticular, blue colors having L values between about 60 and about 85,a* between about −3.0 and −12.0, and b* between about −6.5 and about−15.0 are particularly useful in the present invention. These L, a* andb* values are as measured using as measured by a Minolta CR-321 colormeasurement system, using the 3 mm aperture, directly from the layer towhich the color is applied.

When measured from the body facing surface of the article, the coloredportions 802 and 804 preferably has an L value of between about 80 andabout 92, an a* value of between about −6.0 and −3.5 and a b* value ofbetween about −5.0 and about −10.0. More preferably, the colored portionhas an L value of between about 85 and about 92, an a* value of betweenabout −5.5 and about −4.0, and a b* value of between about −7.0 and−9.0.

Each of the cover layer 842, first absorbent layer 846, second absorbentlayer, and barrier layer 850 layers is described in further detailbelow.

Cover Layer

The cover layer 842 is preferably an apertured film material and morepreferably the cover layer 842 is an apertured film material of the typedescribed in greater detail below with reference to FIGS. 1 a-1 j. Apreferred apertured film cover layer for use in the present invention iscommercially available on the Stayfree DryMax Ultrathin Napkin,distributed by the Personal Products Company division of McNeil-PPC,Inc., Skillman, N.J.

Reference is now made to FIGS. 1 a-1 d which depict an apertured film 10according to one embodiment of the present invention. The film 10includes a plurality of repeating interconnected frames 12. In theembodiment shown in FIGS. 1 a-1 d, each frame 12 includes opposed endregions 12 a and 12 b and opposed side walls 12 c and 12 d. Each of theend regions 12 a and 12 b being in spaced relationship to one anotherand each of the opposed side walls 12 c and 12 d being in spacedrelationship to one another. In the specific embodiment shown in FIGS. 1a-1 d, each of the frames 12 are interconnected to an adjacent frame 12.More particularly, as shown, each frame 12 “shares” a common side wall12 c, 12 d, with a directly adjacent frame 12. Likewise, each frame 12shares a common end region 12 a, 12 b with a directly adjacent frame 12.The apertured film 10 further includes first and second cross members 14a and 14 b. As shown, cross member 14 b extends from a first side wall12 c to an opposed side wall 12 d of the frame 12. Likewise, crossmember 14 a extends from an end region 12 a to the opposed end region 12b. In the embodiment of the invention shown in FIGS. 1 a-1 e, the crossmembers 14 a and 14 b intersect at the center of the frame is shown. Inaddition, in the embodiment of the invention shown in FIGS. 1 a-1 e, thecross members 14 a and 14 b are orthogonally arranged to one another.

Although the embodiment of the invention shown in FIGS. 1 a-1 d showsthe apertured film 10 as having two cross members 14 a and 14 b, it ispossible that only a single cross member could be employed as long asthe cross member extends across the open area defined by the frame 12.Also, although the frame 12 has been shown as being generally hexagonalin shape, it is possible that other shapes could be used for the frame12. Each of the cross members 14 a and 14 b preferably have a width “a”(See FIG. 1 b) in the range of about 4.0 mils to about 24.0 mils (1mil=0.001 inch). Each of the cross members 14 a and 14 b preferably havea length “b” (See FIG. 1 b) in the range of about 30.0 mils to about150.0 mils. The film 10 may optionally include a plurality of bumps 11or the like arranged on the surface of the film as best seen in FIG. 1a.

The film 10 further includes a plurality of apertures 16. Each aperture16 is bound by at least a portion of the frame 12 and at least a portionof one of the cross members 14 a and 14 b. Reference is now made to FIG.1 b which is an illustration of a partially broken away perspective viewof the film 10 shown in FIG. 1 taken along line 1B of FIG. 1 a. Eachaperture is bound by at least a portion of each of the cross members 14a and 14 b as well as by a portion of the frame 12. More particularly,as best seen in FIG. 1 b, each of the apertures 16 is bound by acorresponding interior wall 22, 24 of a respective side wall 12 c, 12 dof the frame portion 12. Each aperture 16 is further bound by acorresponding interior wall 26 or 28 of cross member 14 b and acorresponding interior wall 30, 32 of cross member 14 a. Finally, eachaperture 16 is bound by a respective interior wall 34, 36 of acorresponding end region 12 a, 12 b.

Again referring to FIG. 1 b, film 10 generally includes a firstgenerally planar top surface 18 in imaginary plane 23 and an opposed,generally planar, second bottom surface 21 in imaginary plane 25. Thetop surface 38 of the side walls 12 c and 12 d and the top surface 40 ofthe end regions 12 a and 12 b are coplanar with plane 23. However, thetop surfaces 42 and 44 of cross members 14 a and 14 b are recessedrelative to plane 23. More particularly, the top surfaces 42 and 44 ofcross members 14 a and 14 b are located in a plane 27 located below bothplanes 23 and 25. Preferably the top surfaces 42 and 44 of the crossmembers 14 a and 14 b are recessed relative to the top surface 18 of thefilm, i.e. recessed relative to plane 23, to a depth in the range ofabout 3.0 mils to about 17.0 mils. The top surfaces 42 and 44 of crossmembers 14 a and 14 b are preferably substantially parallel to theimaginary planes 23 and 25.

The interior walls 22, 24 of side walls 12 c and 12 d, interior walls26, 28 of cross member 14 a, interior walls 30, 32 of cross member 14 b,and interior walls 34, 36 of end regions 12 a, 12 b cooperate to definethe apertures 16 and each of these interior walls extend below plane 25such that the bottom opening of each aperture 16 is located below thebottom planar surface 21 of the film, i.e., below imaginary plane 25.More specifically, interior walls 22, 24 of side walls 12 c and 12 d,interior walls 26, 28 of cross member 14 a, interior walls 30, 32 ofcross member 14 b, and interior walls 34, 36 of end regions 12 a, 12 bextend downwardly such that the bottom opening of each aperture islocated in imaginary plane 29 which is located below imaginary planes23, 25 and 27. It is noted that imaginary planes 23, 25, 27 and 29 areall substantially parallel to one another.

Since the top surfaces 42, 44 of the cross members 14 a and 14 b arerecessed relative to the top surface 18 of the film 10, i.e. recessedrelative to imaginary plane 23, a first relatively large aperture iseffectively defined from the top surface 18 of the film 10 to the topsurfaces 42, 44 of the cross members. The cross members 14 a and 14 bact to divide this larger aperture into four relatively smallerapertures which are in communication with the larger aperture from thetop surfaces 42, 44 of the cross members 14 a and 14 b through thebottom opening of each aperture 16. Stated another way, within eachframe member 12, a relatively large aperture is defined from plane 23 toplane 27 and a plurality of relatively smaller apertures, that arecommunication with the larger aperture, are defined from plane 27 toplane 29. In the embodiment shown in FIGS. 1 a-1 d, each of the smallerapertures defined from plane 27 to plane 29 have an area that is lessthan one quarter of the total area of the larger aperture defined fromplane 23 to 27. In an embodiment in which a single cross member wasemployed, each of the smaller apertures defined by the cross memberwould have an area less than one half the total area of the largeraperture. The reader is advised that for simplicity and clarity in thedrawings, both the “smaller” and “larger” apertures discussed above aregenerally identified by reference numeral 16 herein.

Reference is now made to FIGS. 1 e-1 j which depict an apertured film100 according to a second embodiment of the present invention. The sameor similar reference numbers are used in FIGS. 1 e-1 j as those used inFIGS. 1 a-1 d to identify the same and/or corresponding structure asidentified in FIGS. 1 a-1 d and described above.

As best seen in FIGS. 1 e and 1 g, the film 100 includes at least afirst portion 102 and at least a second portion 104. The first portion102 is defined by a plurality of repeating interconnected frames 12defining a plurality of apertures 16 as described above. In theembodiment shown in FIGS. 1 e-1 j, each frame 12 includes opposed endregions 12 a and 12 b and opposed side walls 12 c and 12 d. Theapertured film 100 also includes first and second cross members 14 a and14 b. The cross members 14 a and 14 b preferably have a width “a” in therange of about 4.0 mils to about 24.0 mils. Each of the cross members 14a and 14 b preferably have a length “b” in the range of about 30.0 milsto about 150.0 mils. Preferably the top surfaces 42 and 44 of the crossmembers 14 a and 14 b are recessed relative to the top surface 18 of thefilm, i.e. recessed relative to plane 23, to a depth in the range ofabout 3.0 mils to about 17.0 mils.

Referring to FIG. 1 f, the film 100 generally includes a substantiallyplanar top surface 18 in imaginary plane 23 and an opposed,substantially planar, second bottom surface 21 in imaginary plane 25.The end regions 12 a and 12 b, and the portions 12 c′ and 12 d′ of theside walls 12 c and 12 d in the areas where the cross member 14 bintersects with the side wall 12 c and 12 d, are formed such that at aleast a portion of the top surface of the film in these areas isrecessed relative to the imaginary plane 23. In the particularembodiment of the film 100 shown in FIG. 1 f, the end regions 12 a and12 b, and the portions 12 c′ and 12 d′ of the side walls 12 c and 12 din the areas where the cross member 14 b intersects with the side wall12 c and 12 d, have a substantially “w” shape, or sinusoidal shape,cross section defining a pair of swales 111 and a peak 113 arrangedbetween the swales 111. As shown, the top surface of the film 115 in thearea of the swales 111 is located in a plane 35 which is recessedrelative to the imaginary plane 23. In particular, plane 35 is locatedbetween plane 23 and plane 25. Preferably the swales 111, at their mostrecessed point relative to plane 23, have a depth in the range of about2 to about 5 mils, relative to plane 23.

Although in the particular embodiment 100 the end regions 12 a and 12 band the portions 12 c′ and 12 d′ of the side walls 12 c and 12 d in theareas where the cross member 14 b intersects with the side wall 12 c and12 d are formed to have a substantially “w” shaped cross section, theseareas may be formed to have other shapes and configurations wherein atleast a portion of the top surface of the film in the those areas wherethe cross members 14 a and 14 b intersect the frame 12 is recessedrelative to plane 23. By forming the film 100 in those areas where thecross member 14 a intersects the end regions 12 a and 12 b, and in thoseareas where the cross member 14 b intersects the side walls 12 c and 12d, such that at least a portion thereof is recessed relative to plane 23the perceived softness of the film is enhanced. Although in the specificembodiment of the invention shown in FIG. 1 f the film 100 is formed inthe end regions 12 a and 12 b, and in the portions 12 c′ and 12 d′ ofthe side walls 12 c and 12 d, such that at least a portion of thesurface of the film is recessed relative to plane 23 it is possible toconstruct the film such that only one of these regions is recessedrelative to plane 23. For example only portions 12 c′ and 12 d′ may berecessed or in the alternative only end regions 12 a and 12 b may berecessed.

As best seen in FIG. 1 e, the second portion 104 of the apertured film100 a includes a second plurality of apertures 106 that are visuallydistinguishable from the first plurality of apertures 16. The term“visually distinguishable” as used herein means that each of the secondplurality of apertures 106 has a shape and/or size that is sufficientlydifferent from the shape and/or size of each of the apertures 16 of thefirst plurality of apertures 16 such that, when observed by the nakedeye, each of the second plurality of apertures 106 is visuallydistinguishable from each of the first plurality of apertures 16. In oneembodiment of the invention, shown in FIGS. 1 e-1 j each of the secondplurality of apertures 106 has a generally elliptical shape with a majoraxis “y” and a minor axis “z”. Each of the major axis “y” and minor axis“z” preferably have a length in the range of about 5 mils to about 150mils. In one specific embodiment, the major axis has a length of about43 mils and the minor axis has a length of about 16 mils. In onepreferred embodiment of the invention, each of the second plurality ofapertures 106 are spaced from one another by a distance “n” of about 10mils to about 100 mils when measured from the center of one aperture tothe center of a horizontally adjacent aperture along a horizontal line,and each of the second plurality of apertures 106 are spaced from avertically adjacent aperture 106 by a distance “o” of about 10 mils toabout 70 mils when measured from the center of one aperture to thecenter of a vertically adjacent aperture along a diagonal connecting thecenter of each of the apertures. In a specific embodiment of theinvention, the distance “n” is 40 mils and the distance “o” is 34 mils.

The second plurality of apertures 106 may be arranged in a pattern todefine a design, indicia, text or the like, or combinations thereof. Forexample, in the embodiment of the invention shown in FIGS. 1 e and 1 g,the second plurality of apertures 106 are arranged to define a butterflydesign. Although in the particular embodiment of the invention shown anddescribed with reference to FIGS. 1 e-1 j, a butterfly design isdepicted, any other number of designs are possible.

The film 100 shown in FIGS. 1 e-1 j is also provided with a border 108that separates the first plurality of apertures 16 from the secondplurality of apertures 106. Preferably, the border has a shape and sizesuch that it is visually distinguishable, when viewed by the naked eye,from each of the first plurality of apertures 16 and each of the secondplurality of apertures 106. Preferably the border 108 has a width “x”(See FIG. 1 e) in the range of between about 25 mils and 90 mils. In onepreferred embodiment of the invention the border 108 is not apertured.The surface of the film 109 located within the area defined by theborder 108 is preferably recessed related to the top substantiallyplanar surface 18 of the film. In other words, the surface of the film109 bound within the border 108 is recessed relative to plane 23.Preferably the surface of the film 109 is recessed relative to plane 23in an amount from about 2 mils to about 5 mils. The surface of the filmdefining the border 108 itself is preferably located within plane 23.

Preferably the border 108 cooperates with the second plurality ofapertures 106 to visually define the design, indicia, text or the like.For example, in the embodiment of the film 100 shown, the bordercooperates with the second plurality of apertures 106 to define abutterfly design.

Although a single butterfly is shown in FIG. 1 e for simplicity aplurality of such elements may be spaced over the surface of the film.For example, in one specific embodiment the film may have a plurality ofsuch butterflies spaced over the film material. In addition, differentsized designs may be employed, for example in one specific embodiment aplurality of relatively large butterflies and a plurality of smallerbutterflies are employed in the same film.

The apertured films according to the present invention preferably havean open area in the range about 20% to about 30%. Open area may bedetermined by using image analysis to measure the relative percentagesof apertured and unapertured, or land, areas. Essentially image analysisconverts an optical image from a light microscope into an electronicsignal suitable for processing. An electronic beam scans the image,line-by-line. As each line is scanned, an output signal changesaccording to illumination. White areas produce a relatively high voltageand black areas a relatively low voltage. An image of the aperturedformed film is produced and, in that image, the holes are white, whilethe solid areas of thermoplastic material are at various levels of gray.

The more dense the solid area, the darker the gray area produced. Eachline of the image that is measured is divided into sampling points orpixels. The following equipment can be used to carry out the analysisdescribed above: a Quantimet Q520 Image Analyzer (with v. 5.02B softwareand Grey Store Option), sold by LEICA/Cambridge Instruments Ltd., inconjunction with an Olympus SZH Microscope with a transmitted lightbase, a plan 1.0.times objective, and a 2.50 times eyepiece. The imagecan be produced with a DAGE MTI CCD72 video camera.

A representative piece of each material to be analyzed is placed on themicroscope stage and sharply imaged on the video screen at a microscopezoom setting of 10 times. The open area is determined from fieldmeasurements of representative areas. The Quantimet program outputreports mean value and standard deviation for each sample.

A suitable starting film for making a three-dimensional apertured filmaccording to the present invention is a thin, continuous, uninterruptedfilm of thermoplastic polymeric material. This film may be vaporpermeable or vapor impermeable; it may be embossed or unembossed; it maybe corona-discharge treated on one or both of its major surfaces or itmay be free of such corona-discharge treatment; it may be treated with asurface active agent after the film is formed by coating, spraying, orprinting the surface active agent onto the film, or the surface activeagent may be incorporated as a blend into the thermoplastic polymericmaterial before the film is formed. The film may comprise anythermoplastic polymeric material including, but not limited to,polyolefins, such as high density polyethylene, linear low densitypolyethylene, low density polyethylene, polypropylene; copolymers ofolefins and vinyl monomers, such as copolymers of ethylene and vinylacetate or vinyl chloride; polyamides; polyesters; polyvinyl alcohol andcopolymers of olefins and acrylate monomers such as copolymers ofethylene and ethyl acrylate and ethylenemethacrylate. Films comprisingmixtures of two or more of such polymeric materials may also be used.The machine direction (MD) and cross direction (CD) elongation of thestarting film to be apertured should be at least 100% as determinedaccording to ASTM Test No. D-882 as performed on an Instron testapparatus with a jaw speed of 50 inches/minute (127 cm/minute). Thethickness of the starting film is preferably uniform and may range fromabout 0.5 to about 5 mils or about 0.0005 inch (0.0013 cm) to about0.005 inch (0.076 cm). Coextruded films can be used, as can films thathave been modified, e.g., by treatment with a surface active agent. Thestarting film can be made by any known technique, such as casting,extrusion, or blowing.

A method of aperturing the films according to the present inventioninvolves placing the film onto the surface of a patterned supportmember. The film is subjected to a high fluid pressure differential asit is on the support member. The pressure differential of the fluid,which may be liquid or gaseous, causes the film to assume the surfacepattern of the patterned support member. If the patterned support memberhas apertures therein, portions of the film overlying the apertures maybe ruptured by the fluid pressure differential to create an aperturedfilm. A method of forming an apertured film is described in detail inU.S. Pat. No. 5,827,597 to James et al., incorporated herein byreference.

Such a three dimensional apertured film is preferably formed by placinga thermoplastic film across the surface of an apertured support memberwith a pattern corresponding to desired final film shape. A stream ofhot air is directed against the film to raise its temperature to causeit to be softened. A vacuum is then applied to the film to cause it toconform to the shape of the surface of the support member. Portions ofthe film lying over the apertures in the support member are furtherelongated until rupture to create apertures in the film.

A suitable apertured support member for making these three-dimensionalapertured films is a three-dimensional topographical support member madeby laser sculpting a workpiece. A schematic illustration of an exemplaryworkpiece that has been laser sculpted into a three dimensionaltopographical support member is shown in FIG. 2.

The workpiece 102 comprises a thin tubular cylinder 110. The workpiece102 has non-processed surface areas 111 and a laser sculpted centerportion 112. A preferred workpiece for producing the support member ofthis invention is a thin-walled seamless tube of acetal, which has beenrelieved of all residual internal stresses. The workpiece has a wallthickness of from 1-8 mm, more preferably from 2.5-6.5 mm. Exemplaryworkpieces for use in forming support members are one to six feet indiameter and have a length ranging from two to sixteen feet. However,these sizes are a matter of design choice. Other shapes and materialcompositions may be used for the workpiece, such as acrylics, urethanes,polyesters, high molecular weight polyethylene and other polymers thatcan be processed by a laser beam.

Referring now to FIG. 3, a schematic illustration of an apparatus forlaser sculpting the support member is shown. A starting blank tubularworkpiece 102 is mounted on an appropriate arbor, or mandrel 121 thatfixes it in a cylindrical shape and allows rotation about itslongitudinal axis in bearings 122. A rotational drive 123 is provided torotate mandrel 121 at a controlled rate. Rotational pulse generator 124is connected to and monitors rotation of mandrel 121 so that its preciseradial position is known at all times.

Parallel to and mounted outside the swing of mandrel 121 is one or moreguide ways 125 that allow carriage 126 to traverse the entire length ofmandrel 121 while maintaining a constant clearance to the top surface103 of workpiece 102. Carriage drive 133 moves the carriage along guideways 125, while carriage pulse generator 134 notes the lateral positionof the carriage with respect to workpiece 102. Mounted on the carriageis focusing stage 127. Focusing stage 127 is mounted in focus guide ways128. Focusing stage 127 allows motion orthogonal to that of carriage 126and provides a means of focusing lens 129 relative to top surface 103.Focus drive 132 is provided to position the focusing stage 127 andprovide the focusing of lens 129.

Secured to focusing stage 127 is the lens 129, which is secured innozzle 130. Nozzle 130 has means 131 for introducing a pressurized gasinto nozzle 130 for cooling and maintaining cleanliness of lens 129. Apreferred nozzle 130 for this purpose is described in U.S. Pat. No.5,756,962 to James et al. which is incorporated herein by reference.

Also mounted on the carriage 126 is final bending mirror 135, whichdirects the laser beam 136 to the focusing lens 129. Remotely located isthe laser 137, with optional beam bending mirror 138, to direct the beamto final beam bending mirror 135. While it would be possible to mountthe laser 137 directly on carriage 126 and eliminate the beam bendingmirrors, space limitations and utility connections to the laser makeremote mounting far preferable.

When the laser 137 is powered, the beam 136 emitted is reflected byfirst beam bending mirror 138, then by final beam bending mirror 135,which directs it to lens 129. The path of laser beam 136 is configuredsuch that, if lens 129 were removed, the beam would pass through thelongitudinal center line of mandrel 121. With lens 129 in position, thebeam may be focused above, below, at, or near top surface 103.

While this apparatus could be used with a variety of lasers, thepreferred laser is a fast flow CO₂ laser, capable of producing a beamrated at up to 2500 watts. However, slow flow CO₂ lasers rated at 50watts could also be used.

FIG. 4 is a schematic illustration of the control system of the lasersculpting apparatus of FIG. 3. During operation of the laser sculptingapparatus, control variables for focal position, rotational speed, andtraverse speed are sent from a main computer 142 through connection 144to a drive computer 140. The drive computer 140 controls focus positionthrough focusing stage drive 132. Drive computer 140 controls therotational speed of the workpiece 102 through rotational drive 123 androtational pulse generator 124. Drive computer 140 controls the traversespeed of the carriage 126 through carriage drive 133 and carriage pulsegenerator 134. Drive computer 140 also reports drive status and possibleerrors to the main computer 142. This system provides positive positioncontrol and in effect divides the surface of the workpiece 102 intosmall areas called pixels, where each pixel consists of a fixed numberof pulses of the rotational drive and a fixed number of pulses of thetraverse drive. The main computer 142 also controls laser 137 throughconnection 143.

A laser sculpted three dimensional topographical support member may bemade by several methods. One method of producing such a support memberis by a combination of laser drilling and laser milling of the surfaceof a workpiece.

Methods of laser drilling a workpiece include percussion drilling,fire-on-the-fly drilling, and raster scan drilling.

A preferred method is raster scan drilling. In this approach, thepattern is reduced to a rectangular repeat element 141, an example ofwhich is depicted in FIG. 11. This repeat element contains all of theinformation required to produce the desired pattern. When used like atile and placed both end-to-end and side-by-side, the larger desiredpattern is the result.

The repeat element 141 is further divided into a grid of smallerrectangular units or “pixels” 142. Though typically square, for somepurposes, it may be more convenient to employ pixels of unequalproportions. The pixels themselves are dimensionless and the actualdimensions of the image are set during processing, that is, the width145 of a pixel and the length 146 of a pixel are only set during theactual drilling operation. During drilling, the length of a pixel is setto a dimension that corresponds to a selected number of pulses from thecarriage pulse generator 134. Similarly, the width of a pixel is set toa dimension that corresponds to the number of pulses from the rotationalpulse generator 124. Thus, for ease of explanation, the pixels are shownto be square in FIG. 5 a; however, it is not required that pixels besquare, but only that they be rectangular.

Each column of pixels represents one pass of the workpiece past thefocal position of the laser. This column is repeated as many times as isrequired to reach completely around workpiece 102. A white pixelrepresents an off instruction to the laser and each black pixelrepresents an on instruction to the laser. This results in a simplebinary file of 1's and 0's where a 1, or white, is an instruction forthe laser to shut off and a 0, or black, is an instruction for the laserto turn on.

Referring back to FIG. 4, the contents of an engraving file are sent ina binary form where 1 is off and 0 is on by the main computer 142 to thelaser 137 via connection 143. By varying the time between eachinstruction, the duration of the instruction is adjusted to conform tothe size of the pixel. After each column of the file is completed, thatcolumn is again processed, or repeated, until the entire circumferenceis completed. While the instructions of a column are being carried out,the traverse drive is moved slightly. The speed of traverse is set sothat upon completion of a circumferential engraving, the traverse drivehas moved the focusing lens the width of a column of pixels and the nextcolumn of pixels is processed. This continues until the end of the fileis reached and the file is again repeated in the axial dimension untilthe total desired width is reached.

In this approach, each pass produces a number of narrow cuts in thematerial, rather than a large hole. Because these cuts are preciselyregistered to line up side-by-side and overlap somewhat, the cumulativeeffect is a hole.

A highly preferred method for making the laser sculpted threedimensional topographical support members is through laser modulation.Laser modulation is carried out by gradually varying the laser power ona pixel by pixel basis. In laser modulation, the simple on or offinstructions of raster scan drilling are replaced by instructions thatadjust on a gradual scale the laser power for each individual pixel ofthe laser modulation file. In this manner, a three dimensional structurecan be imparted to the workpiece in a single pass over the workpiece.

Laser modulation has several advantages over other methods of producinga three dimensional topographical support member. Laser modulationproduces a one-piece, seamless, support member without the patternmismatches caused by the presence of a seam. With laser modulation, thesupport member is completed in a single operation instead of multipleoperations, thus increasing efficiency and decreasing cost. Lasermodulation eliminates problems with the registration of patterns, whichcan be a problem in a multi-step sequential operation. Laser modulationalso allows for the creation of topographical features with complexgeometries over a substantial distance. By varying the instructions tothe laser, the depth and shape of a feature can be precisely controlledand features that continuously vary in cross section can be formed.Also, with laser sculpting the regular positions of the aperturesrelative to one another can be maintained.

Referring again to FIG. 4, during laser modulation the main computer 142may send instructions to the laser 137 in other than a simple “on” or“off” format. For example, the simple binary file may be replaced withan 8 bit (byte) format, which allows for a variation in power emitted bythe laser of 256 possible levels. Utilizing a byte format, theinstruction “11111111” instructs the laser to turn off, “00000000”instructs the laser to emit full power, and an instruction such as“10000000” instructs the laser to emit one-half of the total availablelaser power.

A laser modulation file can be created in many ways. One such method isto construct the file graphically using a gray scale of a 256 colorlevel computer image. In such a gray scale image, black can representfull power and white can represent no power with the varying levels ofgray in between representing intermediate power levels. A number ofcomputer graphics programs can be used to visualize or create such alaser-sculpting file. Utilizing such a file, the power emitted by thelaser is modulated on a pixel by pixel basis and can therefore directlysculpt a three dimensional topographical support member. While an 8-bitbyte format is described here, other levels, such as 4 bit, 16 bit, 24bit or other formats can be substituted.

A suitable laser for use in a laser modulation system for lasersculpting is a fast flow CO₂ laser with a power output of 2500 watts,although a laser of lower power output could be used. Of primary concernis that the laser must be able to switch power levels as quickly aspossible. A preferred switching rate is at least 10 kHz and even morepreferred is a rate of 20 kHz. The high power-switching rate is neededto be able to process as many pixels per second as possible.

FIG. 5 is a graphical representation of a laser modulation file,including a repeat element 141 a, that may be used to form a supportmember for forming the apertured film shown in FIGS. 1 a-1 e. FIG. 5 ais an enlarged portion of the laser modulation file shown in FIG. 5.

FIG. 5 b is a graphical representation of a laser modulation file,including a repeat element 141 b, that may be used to form a supportmember for forming the apertured film shown in FIGS. 1 e-1 j. FIG. 5 cis an enlarged portion of the laser modulation file shown in FIG. 5 bcorresponding to the portion of file encircled by the circle “5c” inFIG. 5 b. FIG. 5 d is an enlarged portion of the laser modulation fileshown in FIG. 5 b corresponding to the portion of file encircled by thecircle “5d” in FIG. 5 b. FIG. 5 e is an enlarged portion of the lasermodulation file shown in FIG. 5 b corresponding to the portion of fileencircled by the circle “5e” in FIG. 5 d.

In FIGS. 5 through 5 e the black areas 154 a indicate pixels where thelaser is instructed to emit full power, thereby creating a hole in thesupport member, which corresponds to apertures 16 in thethree-dimensional apertured film 10 illustrated in FIGS. 1 a-1 d. Thelight gray areas 155 indicate pixels where the laser receivesinstructions to apply a very low level power, thereby leaving thesurface of the support member essentially intact. These areas of thesupport member correspond to the protuberances 11 shown in FIG. 1 a. Theother areas depicted in FIGS. 5-5 e, which are depicted in variouslevels of gray, represent corresponding levels of laser power andcorrespond to various features of the films 10 and 100 shown in FIGS. 1a-1 d and FIGS. 1 e- 1 j respectively. For example, areas 157 and 159correspond to cross members 14 a and 14 b of the film 10 and the film100.

FIG. 6 is a photomicropgraph of a portion 161 of a support member afterit was engraved using the file shown in FIG. 5. The pattern on theportion of support member shown in FIG. 6 is repeated over the surfaceof the support member to thereby produce the repeating pattern of thefilm 10 shown in FIGS. 1 a-1 d.

FIG. 6 a is a photomicropgraph of a portion 162 of a support memberafter it was engraved using the file shown in FIG. 5. The pattern on theportion of support member shown in FIG. 6 a is repeated over the surfaceof the support member to thereby produce a film having repeatingbutterfly pattern of the type shown in FIGS. 1 e-1 j. FIG. 6 b is anenlarged portion of the support member shown in FIG. 6 a correspondingto the portion of the support member in FIG. 6 a encircled by the circle“6”b. Upon completion of the laser sculpting of the workpiece, it can beassembled into the structure shown in FIG. 7 for use as a supportmember. Two end bells 235 are fitted to the interior of the workpiece236 with laser sculpted area 237. These end bells can be shrink-fit,press-fit, attached by mechanical means such as straps 238 and screws239 as shown, or by other mechanical means. The end bells provide amethod to keep the workpiece circular, to drive the finished assembly,and to fix the completed structure in the aperturing apparatus.

A preferred apparatus for producing such three dimensional aperturedfilms is schematically depicted in FIG. 8. As shown here, the supportmember is a rotatable drum 753. In this particular apparatus, the drumrotates in a counterclockwise direction. Positioned outside drum 753 isa hot air nozzle 759 positioned to provide a curtain of hot air toimpinge directly on the film supported by the laser sculpted supportmember. Means is provided to retract hot air nozzle 759 to avoidexcessive heating of the film when it is stopped or moving at slowspeed. Blower 757 and heater 758 cooperate to supply hot air to nozzle759. Positioned inside the drum 753, directly opposite the nozzle 759,is vacuum head 760. Vacuum head 760 is radially adjustable andpositioned so as to contact the interior surface of drum 753. A vacuumsource 761 is provided to continuously exhaust vacuum head 760.

Cooling zone 762 is provided in the interior of and contacting the innersurface of drum 753. Cooling zone 762 is provided with cooling vacuumsource 763. In cooling zone 762, cooling vacuum source 763 draws ambientair through the apertures made in the film to set the pattern created inthe aperturing zone. Vacuum source 763 also provides means of holdingthe film in place in cooling zone 762 in drum 753 and provides means toisolate the film from the effects of tension produced by winding up thefilm after its aperturing.

Placed on top of laser sculpted support member 753 is a thin,continuous, uninterrupted film 751 of thermoplastic polymeric material.

An enlargement of the circled area of FIG. 8 is shown in FIG. 9. Asshown in this embodiment, vacuum head 760 has two vacuum slots 764 and765 extending across the width of the film. However, for some purposes,it may be preferred to use separate vacuum sources for each vacuum slot.As shown in FIG. 23, vacuum slot 764 provides a hold down zone for thestarting film as it approaches air knife 758. Vacuum slot 764 isconnected to a source of vacuum by a passageway 766. This anchors theincoming film 751 securely to drum 753 and provides isolation from theeffects of tension in the incoming film induced by the unwinding of thefilm. It also flattens film 751 on the outer surface of drum 753. Thesecond vacuum slot 765 defines the vacuum aperturing zone. Immediatelybetween slots 764 and 765 is intermediate support bar 768. Vacuum head760 is positioned such that the impingement point of hot air curtain 767is directly above intermediate support bar 768. The hot air is providedat a sufficient temperature, a sufficient angle of incidence to thefilm, and at a sufficient distance from the film to cause the film tobecome softened and deformable by a force applied thereto. The geometryof the apparatus ensures that the film 751, when softened by hot aircurtain 767, is isolated from tension effects by hold-down slot 764 andcooling zone 762 (FIG. 22). Vacuum aperturing zone 765 is immediatelyadjacent hot air curtain 767, which minimizes the time that the film ishot and prevents excessive heat transfer to support member 753.

Referring to FIGS. 8 and 9, a thin flexible film 751 is fed from asupply roll 750 over idler roll 752. Roll 752 may be attached to a loadcell or other mechanism to control the feed tension of the incoming film751. The film 751 is then placed in intimate contact with the supportmember 753. The film and support member then pass to vacuum zone 764. Invacuum zone 764 the differential pressure further forces the film intointimate contact with support member 753. The vacuum pressure thenisolates the film from the supply tension. The film and support membercombination then passes under hot air curtain 767. The hot air curtainheats the film and support member combination thus softening the film.

The heat-softened film and the support member combination then pass intovacuum zone 765 where the heated film is deformed by the differentialpressure and assumes the topography of the support member. The heatedfilm areas that are located over open areas in the support member arefurther deformed into the open areas of the support member. If the heatand deformation force are sufficient, the film over the open areas ofthe support member is ruptured to create apertures.

The still-hot apertured film and support member combination then passesto cooling zone 762. In the cooling zone a sufficient quantity ofambient air is pulled through the now-apertured film to cool both thefilm and the support member.

The cooled film is then removed from the support member around idlerroll 754. Idler roll 754 may be attached to a load cell or othermechanism to control winding tension. The apertured film then passes tofinish roll 756, where it is wound up.

Absorbent System—First Absorbent Layer

U.S. Pat. No. 6,515,195 discuses an absorbent system that may beemployed in the absorbent article according, the subject matter of whichis hereby incorporated by reference.

Adjacent to the cover layer 842 on its inner side and bonded to thecover layer 842 is a first absorbent layer 846 that forms part of theabsorbent system. The first absorbent layer 846 provides the means ofreceiving body fluid from the cover layer 842 and holding it until anunderlying second absorbent layer has an opportunity to absorb the fluidand therefore acts as a fluid transfer or acquisition layer.

The first absorbent layer 846 is, preferably, more dense than and has alarger proportion of smaller pores than the cover layer 842. Theseattributes allow the first absorbent layer 846 to contain body fluid andhold it away from the outer side of the cover layer 842, therebypreventing the fluid from rewetting the cover layer 842 and its surface.However, the first absorbent layer 846 is, preferably, not so dense asto prevent the passage of the fluid through the layer 846 into theunderlying second absorbent layer 848.

The first absorbent layer 846 may be composed of fibrous materials suchas wood pulp, polyester, rayon, flexible foam, or the like, orcombinations thereof. The first absorbent layer 846 may also comprisethermoplastic fibers for the purpose of stabilizing the layer andmaintaining its structural integrity. The first absorbent layer 846 maybe treated with surfactant on one or both sides in order to increase itswettability, although generally the first absorbent layer 846 isrelatively hydrophilic and may not require treatment. The firstabsorbent layer 846 is preferably bonded or adhered on both sides to theadjacent layers, i.e., the cover layer 842 and an underlying secondabsorbent layer 848.

Materials particularly suitable for use in the first absorbent layer 846have a density in the range of about 0.04 to 0.05 g/cc, a basis weightin the range from about 80 to 110 g/m²(gsm), a thickness in the range ofabout 2 to 3 mm and in particular a thickness of 2.6 mm. Examples ofsuitable materials for the first absorbent layer are through air bondedpulp sold by Buckeye of Memphis, Tenn., under the designation VIZORB3008, which has a basis weight of 110 gsm, VIZORB 3010, which has abasis weight of 90 gsm, VIZORB 3003, which has a basis weight of 100gsm, and VIZORB 3042 which has a basis weight of 100 gsm.

Absorbent System--Second Absorbent Layer

Immediately adjacent to and bonded to the first absorbent layer 846 isthe second absorbent layer 848. In one embodiment, the second absorbentlayer 848 is a blend or mixture of cellulosic fibers and superabsorbentdisposed in and amongst fibers of that pulp. In a specific example, thesecond absorbent layer 848 is a material containing from about 40 weightpercent to about 95 weight percent cellulosic fibers and from about 5weight percent to about 60 weight percent SAP (superabsorbent polymers).The material has a water content of less than about 10 weight percent.As used herein, the phrase “weight percent” means weight of substanceper weight of final material. By way of example, 10 weight percent SAPmeans 10 gsm SAP per 100 gsm basis weight of the material.

Cellulosic fibers that can be used in the second absorbent layer 848 arewell known in the art and include wood pulp, cotton, flax and peat moss.Wood pulp is preferred. Pulps can be obtained from mechanical orchemi-mechanical, sulfite, kraft, pulping reject materials, organicsolvent pulps, etc. Both softwood and hardwood species are useful.Softwood pulps are preferred. It is not necessary to treat cellulosicfibers with chemical debonding agents, cross-linking agents and the likefor use in the present material.

The second absorbent layer 848 can contain any superabsorbent polymer(SAP), which SAPs are well known in the art. For the purposes of thepresent invention, the term “superabsorbent polymer” (or “SAP”) refersto materials which are capable of absorbing and retaining at least about10 times their weight in body fluids under a 0.5 psi pressure. Thesuperabsorbent polymer particles of the invention may be inorganic ororganic crosslinked hydrophilic polymers, such as polyvinyl alcohols,polyethylene oxides, crosslinked starches, guar gum, xanthan gum, andthe like. The particles may be in the form of a powder, grains,granules, or fibers. Preferred superabsorbent polymer particles for usein the present invention are crosslinked polyacrylates, such as theproduct offered by Sumitomo Seika Chemicals Co., Ltd. Of Osaka, Japan,under the designation of SA60N Type II*, and the product offered byChemical International, Inc. of Palatine, Ill., under the designation of2100A*.

In a specific example, the second absorbent layer 848 is a materialcontaining from about 40 to about 95 weight percent cellulosic fibersand, more specifically, from about 60 to about 80 weight percentcellulosic fibers. Such a material may contain from about 5 to about 60weight percent SAP, preferably from about 20 to about 55 weight percentSAP, even more preferably from about 30 to about 45 weight percent SAP,and most preferably about 40 weight percent SAP.

In a preferred embodiment, the second absorbent layer 848 ismanufactured by using air-laying means. The second absorbent layer 848of the present invention is of high density and in a specific examplehas a density of greater than about 0.25 g/cc. Specifically, the secondabsorbent layer 848 may have a density in the range of from about 0.30g/cc to about 0.50 g/cc. More specifically, the density is from about0.30 g/cc to about 0.45 g/cc and, even more specifically, from about0.30 g/cc to about 0.40 g/cc.

Air-laid absorbents are typically produced with a low density. Toachieve higher density levels, such as the examples of the secondabsorbent layer 848 given above, the air-laid material is compactedusing calendars. Compaction is accomplished using means well known inthe art. Typically such compaction is carried out at a temperature ofabout 100 degrees C. and a load of about 130 Newtons per millimeter. Theupper compaction roll is typically made of steel while the lowercompaction roll is a flexroll having a hardness of about 85 SH D. It ispreferred that both the upper and lower compaction rolls be smooth,although the upper roll can be engraved.

The second absorbent layer 848 can be prepared over a wide range ofbasis weights. The second absorbent layer 848 can have a basis weight inthe range of from about 100 gsm to about 700 gsm. In a specific example,the basis weight ranges from about 150 gsm to about 400 gsm.

Preferably, the basis weight ranges from about 200 gsm to about 350 gsmand, more preferably, to about 300 gsm. The second absorbent layer 848functions synergistically with the first absorbent layer to reduce therewet potential. The first absorbent layer, having a relatively openpore structure, readily absorbs and disperses liquid laterally withinits bulk and readily transfers the liquid to the receiving surface ofthe second absorbent layer. In turn, the second absorbent layer, havinggood capillarity efficiently draws liquid into its bulk from the firstabsorbent layer. Once the liquid has been absorbed into superabsorbentpolymer, the liquid cannot be subsequently released by applyingpressure. Therefore, the liquid absorbed into the superabsorbentmaterial becomes permanently entrapped. At the same time, the strengthwith which the second absorbent layer intakes liquid from the firstabsorbent layer helps to reduce the proportion of liquid held in thefirst absorbent layer, thereby reducing the amount of liquid thatreturns to the cover layer when the napkin is subjected to mechanicalloading. Furthermore, the first absorbent layer has a relatively highcapillarity so that any concentration of liquid in the first absorbentlayer resulting from mechanical loading can be redistributed within thematerial to lower concentrations, again reducing the amount of liquidwhich can return to the cover layer.

In a specific embodiment, the second absorbent layer contains in therange from about 30 to 40 weight percent superabsorbent material, has abasis weight in the range from about 200 to 400 gsm and a density in therange from about 0.2 to 0.45 g/cc. Even where prepared as from multiplelayers, the final thickness of the formed second absorbent layer 848 islow. The thickness can vary from about 0.5 mm to about 2.5 mm. In aspecific example, the thickness is from about 1.0 mm to about 2.0 mmand, even more specifically, from about 1.25 mm to about 1.75 mm.

For further details on the structure and the method of construction ofthe second absorbent layer 848, the reader is invited to refer to theU.S. Pat. No. 5,866,242 granted on Feb. 2, 1999 to Tan et al. Thecontents of this document are hereby incorporated by reference.

Barrier Layer

Underlying the absorbent system 848 is a barrier layer 850 comprisingliquid-impervious material so as to prevent liquid that is entrapped inthe absorbent system 848 from egressing the sanitary napkin and stainingthe wearer's undergarment. The barrier layer 850 is preferably made ofpolymeric film, although it may be made of liquid-imperviousair-permeable material such as repellent-treated, non-woven ormicroporous films or foams.

The cover layer 842 and the barrier layer 850 are joined along theirmarginal portions so as to form an enclosure or flange seal thatmaintains the absorbent system 848 captive. The joint may be made bymeans of adhesives, heat-bonding, ultrasonic bonding, radio frequencysealing, mechanical crimping, and the like and combinations thereof.

Test Articles

Comparative Test Sample #1—Always Regular Ultrathin, commerciallyavailable from the Procter & Gamble, Co., Cincinnati, Ohio. The AlwaysRegular Ultrathin product includes a substantially centrally arrangedgreen colored area.

Comparative Test Sample #2—Always Regular Maxi, commercially availablefrom the Procter & Gamble, Co., Cincinnati, Ohio. The Always RegularMaxi product includes a substantially centrally arranged blue coloredarea.

Inventive Test Sample #1—An article according the present invention wasconstructed as follows:

(1) Cover Layer—was constructed by first creating an apertured film asdescribed above with reference to FIGS. 1 e-1 j, and described below.The upper surfaces of cross members 14 a and 14 b were recessed relativeto the upper surface of film by 4.5 mils and the width of each crossmember 14 a and 14 b was 5 mils and 9 mils respectively. The length ofeach of the cross members 14 a and 14 b was 100 mils and 60 milsrespectively. The film included a plurality of larger butterfly patternsof the type shown in FIG. 1 e and a plurality of smaller butterflypatterns of the type shown in FIG. 1 e. The size of the larger butterflywas 1.0 inch when measured from the most distal point of one wing to themost distal point of the other wing, and 0.6 inch when measured at themost narrow waist portion of the butterfly. The size of the smallerbutterfly was 0.6 inch when measured from the most distal point of onewing to the most distal point of the other wing, and 0.4 inch whenmeasured at the most narrow waist portion of the butterfly. The largerand smaller butterflies were equally spaced such that a 9 inch(length)×6 inch (width) swatch of the apertured film had 9 large and 9small butterflies equally spaced over the swatch of the film. Each ofthe large and small butterflies included a border 108 and a plurality ofapertures 106 arranged within the area defined by the border. The border108 of each of the larger butterflies had a width of 78 mils and theborder 108 for each of the smaller butterflies had a width of 31 mils.The surface of the film within the area 109 of the film defined by theof the borders 108, for both the larger and smaller butterflies, wasrecessed relative to the top surface of the film by an amount of about4.5 mils. The areas bound by border 109 of both the smaller and largerbutterflies had a plurality of apertures 106, each of the apertures 106having a elliptical shape with a major axis of 43 mils and a minor axisof 16 mils. The distance “n” between horizontally adjacent apertures 106was 40 mils and the distance “o” between vertically adjacent apertureswas 34 mils. (2) Transfer Layer—100 gsm through air bonded pulpcommercially available from Buckeye Technologies Incorporated, Memphis,Tenn., under product code VIZORB 3042. The transfer layer was printed onthe top surface thereof, i.e. cover facing surface, with Acryjet™ fabricink jet CV inks commercially available from Rohm & Haas Co.,Philadelphia, Pa., under product codes RH-10246118 (Black), RH-10246119(Cyan), RH-10246120 (Yellow), RH-10246171 (Magenta). The transfer layerwas printed using a Mimaki Ink Jet Printer and the inks were applied sothat the resultant pattern on the transfer layer corresponded to thecolored portions 802 and 804 of the article shown in FIG. 1. The L, a*and b* values of colored portions of the transfer layer, as measureddirectly from the transfer layer, using a Minolta CR-321 colormeasurement system (SN209810050), using the 3 mm aperture, were L=81.01,a* =−4.87 and b* =−7.99. The transfer layer was constructed so that thetotal absorbent area of the napkin has an area of 15,300 mm , the firstcolored portion had an area of 3,900 mm (26% of the total absorbentarea), and the second colored portion had an area of 1,100 mm² (7% oftotal absorbent area).

(3) A 225 gsm compressed pulp/superabsorbent core, commerciallyavailable from EAM Corporation, Jessup, Ga., under product codeJ2250525.

(4) A 20 gsm polyethylene film barrier commercially available fromPliant Corporation, Schaumburg, Ill., under product code XP-3492B.

Test Fluid

The test fluid used in the test method described below had the followingcomposition:

-   -   (1) 49.45% of 0.9% sodium chloride solution (VWR catalog # VW        3257-7);    -   (2) 49.00% Glycerin (Emery 917);    -   (3) 1% Phenoxyethanol (Clariant Corporation Phenoxetol™);    -   (4) 0.45% Sodium Chloride (Baker sodium chloride crystal        #9624-05);    -   (5) 0.11% FD&C #40 red dye (Waner Jenkinson, South Plainfield,        N.J.).

The percentages provided above are percentages by weight. Test Methodfor Measuring Color Change In Response to Staining Within ColoredPortion of the Article

Five specimens of each of the comparative samples and inventive samplewere tested according to the test method set forth below.

An apparatus capable of measuring L, a* and b* values is required tocarry out test method, a Minolta CR-321 color measurement system, usingthe 3 mm aperture, was employed to determine the L, a* and b* values setforth herein.

Each of the specimens are removed from any packaging and the specimensare conditioned by leaving them in a room that is 21° C., ×1° C. and50%, ±2.0%, relative humidity for a period of one hour.

A specimen for a particular product sample is placed upon a flat surfacewith the cover of the article facing up. L, a* and b* readings are takenof the article at a location intended to placed over the vaginal openingduring use of the product. The aperture of the apparatus should beplaced to it is arranged entirely within the colored area. The L, a* andb* values of the unstained or “clean” napkin are recorded.

A test plate having a centrally arranged elliptical orifice is placed ontop of the cover of the product such that the center of the ellipticalorifice is arranged over the portion of the article intended to beplaced over the vaginal opening during use. The test plate consists of a7.6 cm×25.4 cm plate of 1.3 cm thick polycarbonate with an ellipticalorifice in its center. The elliptical orifice measures 3.8 cm along itsmajor axis and 1.9 cm along its minor axis. A graduated 10 cc syringecontaining 7 cc of test fluid is used to place the test fluid within theelliptical orifice. The test plate is removed once fluid has beenabsorbed and the cover is again visible.

After staining, the article should be permitted to equilibrate at roomtemperature for a period of five minutes. L, a* and b* measurements aretaken over the stained portion article at the location intended toplaced over the vaginal opening during use of the product.

The above described process is repeated for five product samples and theaverage L, a* and b* values for the clean article and stained articleare calculated. After the average L, a* and b* values have beencalculated for both the clean and stained article, the average change inL, i.e. ΔL, the average change in a*, i.e. Δa*, and the average changein b*, i.e. Δb*, are calculated. Tables are provided below setting forththe measured values for Comparative Test Sample #1, Comparative TestSample #2, and Inventive Test Sample #1.

TABLE 1 Comparative Test Sample #1 - Colored Area, Pre-Staining SpecimenL a* b* #1 86.71 −5.97 0.13 #2 87.42 −5.79 0.09 #3 86.59 −6.04 0.22 #487.13 −6.11 0.27 #5 85.73 −6.49 0.60 Average 86.72 −6.08 0.26

TABLE 2 Comparative Test Sample #1 - Colored Area, Post-StainingSpecimen L a* b* #1 67.99 13.85 0.84 #2 65.88 15.80 1.41 #3 67.43 14.440.86 #4 67.44 13.46 0.15 #5 66.83 13.59 0.45 Average 67.11 14.23 0.74

TABLE 3 Comparative Test Sample #1 - Colored Area, Average ΔL, Δa*, Δb*ΔL Δa* Δb* 19.61 20.31 1.00

TABLE 4 Comparative Test Sample #2 - Colored Area, Pre-Staining SpecimenL a* b* #1 87.67 −5.76 −7.64 #2 87.39 −5.05 −7.25 #3 86.62 −5.32 −7.29#4 87.55 −5.64 −7.49 #5 88.16 −5.26 −7.06 Average 87.48 −5.47 −7.35

TABLE 5 Comparative Test Sample #2 - Colored Area, Post-StainingSpecimen L a* b* #1 75.03 12.37 0.64 #2 74.08 13.37 1.40 #3 72.95 14.411.69 #4 71.99 15.52 2.34 #5 70.59 18.08 3.24 Average 72.93 14.75 1.86

TABLE 6 Comparative Test Sample #2 - Colored Area, Average ΔL, Δa*, Δb*ΔL Δa* Δb* 14.55 20.22 9.21

TABLE 7 Inventive Test Sample #1 - Colored Area, Pre-Staining Specimen La* b* #1 90.74 −4.38 −7.49 #2 89.95 −4.35 −7.55 #3 90.03 −4.73 −8.31 #490.35 −4.45 −7.76 #5 90.54 −4.56 −7.64 Average 90.32 −4.49 −7.75

TABLE 8 Inventive Test Sample #1 - Colored Area, Post-Staining SpecimenL a* b* #1 77.11 6.83 −2.18 #2 71.30 6.91 −3.79 #3 76.32 6.94 −2.10 #476.47 5.61 −3.18 #5 78.95 5.75 −2.93 Average 76.03 6.41 −2.84

TABLE 9 Inventive Test Sample #1 - Colored Area, Average ΔL, Δa*, Δb* ΔLΔa* Δb* 14.29 10.90 4.91

As shown above absorbent articles according to the present invention areresistant to red staining, or in other words resistant to Δa*. Inaddition, the colored portion of absorbent articles provide resistanceto red staining while at the same time being “light” in color prior touse. Preferably, the colored portion of the absorbent articles accordingto the present invention has an average L value prior to staining ofL>80 and more preferably L>85. In addition, the inventive article in thecolored portion, after staining, has a Δa* of less than 18, morepreferably less than 15, and most preferably less than 12. In thismanner, the absorbent articles of the present invention provide a clean,light, appearance to the user prior to use while at the same timeminimizing the red characteristics of the stain after use.

Test Method for Measuring Color Change In Response to Staining WithinNoncolored Portion of the Article

After testing each of products within the colored portions of thearticle, each of the articles should be tested in an identical fashionin the noncolored portion of the article. In order to carry out thistest method, five new clean samples of each product to be tested arerequired. Five specimens of each of the comparative samples andinventive sample were tested.

The noncolored portion of the article should be tested for L, *a, and b*values at a noncolored area that is closest to the portion of thearticle adapted to be arranged over the vaginal opening during use. Inthis manner, the article is tested at a noncolored area that is likelyto be stained by menstrual fluid during use. L, a*, and b* values aremeasured for the noncolored portion for five specimens and the averageL, a* and b* values are calculated. Thereafter, the noncolored portionis stained in the same manner described above for with respect to thecolored portion. L, a*, and b* values are recorded for five differentstained specimens and the average L, a*, b* values are recorded.

After the average L, a* and b* values have been calculated for both theclean and stained article, the average change in L, i.e. ΔL, the averagechange in a*, i.e. Δa*, and the average change in b*, i.e. Δb*, arecalculated. Tables are provided below setting forth the measured valuesfor Comparative Test Sample #1, Comparative Test Sample #2, andInventive Test Sample #1.

TABLE 10 Comparative Test Sample #1 - Noncolored Area, Pre-StainingSpecimen L a* b* #1 94.73 −0.81 0.44 #2 95.29 −0.87 0.43 #3 95.09 −0.740.45 #4 95.84 −0.70 0.40 #5 93.82 −0.78 0.45 Average 94.95 −0.78 0.43

TABLE 11 Comparative Test Sample #1 - Noncolored Area, Post-StainingSpecimen L a* b* #1 68.35 15.92 1.64 #2 67.78 16.08 1.50 #3 68.14 15.030.94 #4 67.17 15.39 1.08 #5 67.94 16.11 1.41 Average 67.88 15.71 1.31

TABLE 12 Comparative Test Sample #1 - Noncolored Area, Average ΔL, Δa*,Δb* ΔL Δa* Δb* 27.07 16.49 0.88

TABLE 13 Comparative Test Sample #2 - Noncolored Area, Pre-StainingSpecimen L a* b* #1 97.05 −0.60 1.07 #2 96.17 −0.79 1.89 #3 94.94 −0.821.35 #4 95.30 −0.76 1.51 #5 94.83 −0.88 1.50 Average 95.66 −0.77 1.46

TABLE 14 Comparative Test Sample #2 - Noncolored Area, Post-StainingSpecimen L a* b* #1 72.20 20.91 5.43 #2 72.94 21.84 5.90 #3 73.33 21.425.97 #4 72.63 20.94 4.97 #5 72.16 22.84 6.23 Average 72.65 21.59 5.70

TABLE 15 Comparative Test Sample #2 - Nonolored Area, Average ΔL, Δa*,Δb* ΔL Δa* Δb* 23.01 22.36 4.24

TABLE 16 Inventive Test Sample #1 - Noncolored Area, Pre-StainingSpecimen L a* b* #1 93.10 −0.80 −0.20 #2 95.85 −0.96 1.23 #3 96.84 −0.741.29 #4 96.45 −0.86 1.42 #5 92.73 −0.70 −0.12 Average 94.99 −0.81 0.72

TABLE 17 Inventive Test Sample #1 - Noncolored Area, Post-StainingSpecimen L a* b* #1 76.83 11.02 0.66 #2 77.82 12.68 1.40 #3 77.40 11.661.37 #4 77.60 12.14 1.17 #5 77.20 13.61 2.37 Average 76.97 12.22 1.39

TABLE 18 Inventive Test Sample #1 - Colored Area, Average ΔL, Δa*, Δb*ΔL Δa* Δb* 18.02 13.03 0.67

The above data shows that even the noncolored portions of the napkinaccording the present invention show resistance to red staining asindicated by the low Δa* reading.

1. A sanitary napkin comprising: a body facing surface; a portionadapted to be arranged over the vaginal opening during use; a firstcolored portion, said colored portion extending over at least theportion of the napkin to be placed over the vaginal opening during use;a noncolored portion; wherein said first colored portion has a firstcolor as measured from said body facing surface prior to staining;wherein said first colored portion has a second color as measured fromsaid body facing surface after staining; wherein said first color has anaverage L value greater than 80; and wherein a Δa* between said firstcolor and said second color is less than
 18. 2. The sanitary napkinaccording to claim 1, wherein said Δa* between said first color saidsecond color is less than
 15. 3. The sanitary napkin according to claim1, wherein said Δa* between said first color said second color is lessthan
 12. 4. The sanitary napkin according to claim 1, wherein said firstcolor has an average L value greater than
 85. 5. The sanitary napkinaccording to claim 1, wherein said napkin includes an imaginarylongitudinal centerline and an imaginary transverse centerline and saidfirst colored portion extends along said longitudinal centerline.
 6. Thesanitary napkin according to claim 5, wherein said first colored portionis arranged such that it is symmetrical with respect to the longitudinalcenterline and the transverse centerline.
 7. The sanitary napkinaccording to claim 1, further comprising: a second colored portion. 8.The sanitary napkin according to claim 7, wherein said second coloredportion comprises a ring that extends around said first colored portion.9. The sanitary napkin according to claim 8, wherein said ring is spacedfrom said first colored portion such that a noncolored area is locatedbetween said first colored portion and said second colored portion. 10.The sanitary napkin according to claim 9, wherein said ring has a widthin the range of about 1 mm to about 5 mm.
 11. The sanitary napkinaccording to claim 1, wherein said first colored portion extends overabout 15% to about 40% of the surface of an absorbent portion of thenapkin.
 12. The sanitary napkin according to claim 11, furthercomprising a second colored portion, wherein said second colored portionextends over about 3% to about 12% of the surface of an absorbentportion of the napkin.
 13. The sanitary napkin according to claim 1,further comprising: a cover layer; a barrier layer; and a colored layerarranged between said cover layer and said barrier layer.
 14. Thesanitary napkin according to claim 1, wherein said first color has anaverage L value of between about 80 and about 92, an average a* value ofbetween −6.0 and −3.5 and an average b* value of between about −5.0 andabout −10.
 15. The sanitary napkin according to claim 14, wherein saidfirst color has an average L value of between about 85 and 92, anaverage a* value of between about −5.5 and about −4.0 and an average b*value of between about −7.0 and about −9.0.
 16. The sanitary napkinaccording to claim 1, wherein noncolored portion has an average, L, a*,and b* value as measured from said body facing surface prior tostaining; wherein said noncolored portion has an average, L, a* and b*value as measured from said body facing surface after staining; andwherein a Δa* between the average a* value before staining and theaverage a* value after staining is less than
 16. 17. The sanitary napkinaccording to claim 16, wherein said Δa* is less than
 15. 18. Thesanitary napkin according to claim 16, wherein said Δa* is less than 14.